Elevator for gold-dredgers.



(No Modei.)

Patented July 25, |899. R. H. POSTLETHWAITE.

ELEVATOR FOR GOLD DREDGERS.

(Application tiled Feb. 3, 1898.)

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(No Model.)

UNITED STATES PATENT OFFICE.

ROBERT I-I. POSTLETHWAITE, OF SAN FRANCISCO, CALIFORNIA.

ELEVATOR FOR GOLD-DREDGERS,

SPECIFICATION forming part of lLetters Patent No. 629,602, dated July 25, 1899.

Application iiled February 3, 1898. Serial No. 668,964. (No model.) q

To all whom t may concern:

Be it known that I, ROBERT H. PosTLE- f THWAITE, a subject of the Queen ofl Great Britain, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Elevators for Gold-Dredgers; and I do hereby declare that the following is a full, clear, and exact description thereof.

This invention relates to certain new and useful improvements inelevators for use in connection with that class of dredgers known as gold-dredgers; and it consists in the arrangement of partsanddetails of construction, as will be hereinafter fully set forthin the drawings, and described and pointed outl in the specification.

rlhe invent-ion 'resides mainly in the mechanism for` driving the endless-chain bucketcarrier of the elevator, which is so arranged that the chain carrier is driven through the medium of a single or endless cable operated from the platform, boat', or dredge, the object being to form a direct connection between the drive drum or sheave and the endless-chain bucket-carrier, so as to dispense with the use of counter-shafting in the transmission of power when the drive drum or sheave is out of alinement with the elevator, although the invention also consists in certain details in the construction whereby the endless-chain bucket-carrier is'prevented from sagging as carried around or below the ladder.

In order to fully understand the invention, reference must be had to the accompanying sheets of drawings, forming a part of this application, wherein- Figure l is a side view in elevation of the elevator, showing a portion of the dredge boat, fioat, or platform. Fig. 2 is a rear end view of the boat, platform, or iioat with the elevator removed. Fig. 3 is a top plan view of the ladder over which the endless-chain bucket-carrier works. Fig. 4 is across-sectional end view taken on line ww, Fig. 1'.

Fig. 5 is a detail side view'showinga portion The letter A is used to indicate a boat, plata form, or float, at or near the discharge end of which is secured a vertical sheave-frame A', composed of'suitable uprights and crosspieces, Fig. 2. This sheave-frame supports a series of sheaves or pulleys (hereinafter described) over which runs the cable for driving the endless-chain carrier. p

In a well B2, cut in the discharge end of the boat, platform, or oat A, is secu red the lower end of the elevator-ladder, over which the endless-chain carrier works. This ladder is arranged at an angle to the boat, platform, or dredge, and it consists of the side pieces l 2, cross-pieces 3, and braces 4. Near the 7 upper end of the ladder are placed the square rolls a, mounted upon the shaft a', working in bearing a2, secured to the side pieces 1 2, and near the bottom of the ladder the ihexagon-shaped rolls b, mounted upon the shaft b', working in bearings b2, placed within guides b3, secured to the side pieces of the said ladder, Fig. 3. Over these rolls travels thevendless-chain carrier, consisting of two endless chainsB B, composed of a series of links, which carry the buckets C, attached thereto. The chains composing the endless-,chain carrier between the rolls b and rolls 0L rest upon and are supported by the rolls d, mounted upon the cross-shafts d', secured' in bearings of the brackets C', upwardly projecting from the side pieces 1 2. By means of these supporting-rolls the endless-chain carrier is prevented from sagging as the buckets, with their load, are conveyed upward toward the rolls a. The contents of vthe buckets are discharged as the said buckets move lchain carrier from sagging downward as carried beneath the ladder. In order that the buckets C may clear the underAcross-braces D of the ladder, the said cross-braces are curved downwardly, so as to give clearance for the buckets. The endless-chain carrieris lCO driven by the rotation of the square rolls ct, motion being imparted to the shaft a', carrying the rolls, by means of the pinion D', which meshes with the gear D2, secured to the shaft a. Pinion D' is attached to one end of crossshaft E, working in bearing e, secured to the side pieces l 2, to the opposite end of which shaft is aiixed the sheave E. Motion isimparted to this sheave from the drive-sheave E2, located upon the boat, platform, or iioat, Fig. 6, by means of the single cable E2.

The drive-sheave E2 is mounted upon the shaft F,workingin bearing e, secured toframe F', attached to the boat, platform, or iioat A. This shaft F is driven from anysuitable engine F2. Owing to the location of the rotary screen or grizzly and the collecting-tables usually used in connection with this class of machines it is impossible to place thedrive-sheave E2 without considerable difficulty and crowding of other machinery in line with the sheave E. When out of alinement,as in the present case, it is usual to transmit motion tothe sheave E by means of cross shafting and belting. However, in view of the hard usage to which this class of machinery is exposed, considerable lost motion is occasioned bythe use of cross shafting and beltin g-so much so that itis nearly impossible to transmit a regular movement. To avoid this, I propose to transmit motion from the drive -sheave to the sheave E' to operate the endless-chain carrier bymeans of a single cable E3. In order to successfully transmit power by a single cable, aseries of sheaves is placed within the sheave-frame A' to place the cable Ein alinement with the drive-sheave E2and sheave E.

Upon the cross-shaft e2, working in bearings c2, secured to uprightsfof the sheaveframe, are secured the sheaves 5 6, and upon the cross-shaft f', workingin bearings f2, are secured the sheaves 7 S. Sheaves 5 6 are placed toward the outside of the sheave-frame and sheaves 7 8 toward mthe center thereof. The cross-shafts c2 f being arranged parallel, the said sheaves will revolve in a longitudinal plane. A distance below the said sheaves is located the idler or adjustable sheave 9, which is mounted upon the shaft g, which Works in the slide-boxes g', adjustably secured upon vertical rods g2, held between cross-pieces g2 g4 of the sheave-frame. Above the shaft g is arranged the shaft h, which works in bearing h', secured to the cross-pieces h2. Upon this shaft is mounted the sheave lO, which sheave and the sheave 9 stand at a right-.angle to the sheaves 5 6 7 8. Sheaves 5 6 stand approximately in alinement with the drivesheave E2 and sheaves '7 8 in approximate alinement with sheave E.

The drive-cable runs from drive-sheave E2 over sheave 5, thence downward and under sheave 9, up and over small sheave 7, and outward over sheave E', and back over `large sheave 8, downward under sheave 10, thence upward and over small sheave C, and from said sheave to the drive-sheave. It will thus be observed that the motion of the drivesheave is imparted to the sheave E (out of alinemeut therewith) to drive the endlesschain carrier by means of a single endless cable. l

In case it becomes necessary to tighten or loosen the drive-cable for any cause whatever-as, for instance, to permit of the ladder being raised or lowered-'it is only necessary to loosen the set-screw 7c and lower or raise the idler or adjustable sheave 9.

-The bearings h2 may be raised or lowered in the guides b3 in order to loosen or tighten the endless-chain carriers by simply screwing the screw-bolts 7c', Fig. 1, in or out of the guides h3.

The ladder is held in proper position by means of the cables or tie-rods 7c', which lead from the sheave-frame A', while .the said sheave-frame is held steady by the cables or tie-rods 7a2, which connect with the boat, platform, or float.

By means of the runway or chute K the coarse or base material is conveyed from the rotar screen (not shown) and discharged into the buckets C as the said buckets are carried over the rolls l) by the travel of the endless-chain carrier. As before stated, the buckets empty as carried over the rolls a at the upper end of the ladder, so as to discharge upon an embankment or suitable place of deposit.

Having thus described the invention, what I claim as new, and desire to secure protection in by Letters Patent, is-

1. The combination with a platform andan endless carrier or elevator movably mounted, of a sheave E for im parting motion to the elevator, a drive drum or sheave on said platform out of alinement with said sheave t', a substantially upright sheave-frame on the platform, a series of sheaves working in bearings on said frame, one of said sheaves of the series being adjustable toward and from the others and a single cable for transmitting power from the drive-sheave to the sheave E working onl said sheaves and on the series of sheaves in said frame, substan tially as and for the purpose set forth.

2. The combination with a movably-mounted endless carrier, of a sheave E for imparting motion thereto, a drive-sheave E2 out of alinement with and whose axle is substantially parallel with the axle of the sheave E', a sheave-frame between said sheaves, sheaves 9 and l0 one of which is vertically adjustable mounted on said frame with their axles at an angle to the axles lof sheaves E and E2, sheaves 5, 6, 7 and 8 mounted on said frame with their axles substantially parallel with the axles of the sheaves E' and E2, and a single IOO endless cable passing oversaid sheaves substantially as shown and described and for the purpose set forth.

3. The combination with the ladder, of the rolls secured at the lower and. upper ends thereof, the endless carrier working over said rolls, mechanism for drivin@- said carrier, a series of supporting-rolls for Ehe carrier mounted upon shafts located in brackets secured to and upwardly projecting from the ladder, a series of brackets secured to and depending from the ladder,crossshafts supported by said brackets, rollers mounted upon said shafts, a series of buckets attached to the endless carrier, each bucket being provided With side flanges which rest upon the rolls suspended below the ladder as the carrier moves thereunder. Y

4. The combinationof the ladder, an endless carrier Working thereon comprising a series of buckets each provided with side anges, supportingrollers for the carrier mounted on the ladder upon which rollers said side flanges rest, and drive means.

5. The combination with a support, of an endless carrier thereon having a series of buckets each having in addition to the carrier a fixed supporting-surface, a series of rollers for supporting the under run of buckets and With which the said supporting-surfaces engage, andmeans for driving the carrier.

In testimony whereof I affix my signature, in presence of two Witnesses, this 8th day of January, 1898.

ROBERT H. POSTLETHWAITE.

Witnesses:

N. A. ACKER, LEE D. CRAIG. 

